<!-- from fixya rte -->How much dryer duct do I need? - Whirlpool Cabrio 7.0 Cu. Ft. Super Capacity Plus Gas Dryer

If your old clothes dryer is not working well, how do you tell if it's time to replace it?Here are some things to check before you set it on the curb with a"FREE" sign.
If it still turns on, runs a proper cycle, doesn't make a lot of squeaks and groans, and your clothes are at least attempting to dry, then check the following before you decide to replace.

1. Check and empty your lint trap before each load. If airflow is restricted, your dryer will need longer to get the job done. A clean lint trapwill allow for maximum intake air to the dryer blower.
2. Check the exhaust duct work for lint buildup. If the 4" duct work that carries your warm, moist, lint-laden air to the exterior of your home is blocked with years of lint and moisture, chances are pretty good your dryer is taking longer than it should to get your clothes dry.

• Disconnect the dryer power cord (and gas line if a gas unit), slide the dryer forward far enough to access the 4" duct work clamp at the back of the dryer. Disconnect the duct work at the dryer and separate to inspect both in the dryer exhaust duct and the duct work as well.
• Remove all built up lint. You may need to access under the floor, or in the crawlspace, or basement to get at all the areas that lint may be built up. Remember that when there's an elbow chances are pretty good there's lint in there, so take the time to separate the duct work where needed to give it a thorough clean out.
• Long straight sections of duct work can be easily cleaned by using a Webster-style pole brush.
• Clean the exhaust duct of the dryer but be careful not to damage anything inside your dryer
• Reconnect and turn the dryer on air fluff to blow the rest out.

3. Remove lint build up from inside the machine

• Turn power off again
• Remove the front cover of your dryer
• Remove the front drum support/air duct from the front of the dryer
• Carefully vacuum the lint out of the dryer with soft brush attachment on your vac. Be careful not to damage any igniter or electrical items.
• Clean the inside of the lint trap duct of sediment/ buildup

4. While you've got it open replace the drive belt and check the pulleys.

If this improves your dryer, hang onto it for a while longer! Most times dryers just need a good cleaning and the exhaust duct cleaned. If you're not satisfied with the results, take it to the curb and recycle it to another family.

Here's some useful guidance for installing dryer ducting. Improperly installed ducting can cause the following:

GAS DRYERS - Rapid burn cycling and improper drying results.
ELECTRIC DRYERS - Premature Heating Element failures.

IMPORTANT! NEVER terminate ducting in a chimney, under an enclosed crawl space or attic, and never common a dryer duct with a kitchen exhaust.

The total length of ducting and number of turns should be kept to a minimum. Semi-rigid metal type ducting is strongly recommended as it is more durable and resists collapsing.

If connecting sections of ducting, all joints should be tight to avoid leaks. The male end of each section must point AWAY from the dryer to prevent lint from accumulating at each junction. Ductwork should NOT be assembled with screws or fasteners that extend INTO the duct as this also will create points where lint will become snagged and accumulate. Wrap overlapping sections of ducting with duct tape.

A screen should NEVER be installed over the exhaust duct termination. The preferred termination is a dampered wall cap having a 4 inch opening. It must be installed a minimum of 12 inches above the ground.

Maximum Length of Metal Duct:

# of 90 degree elbows:

4" Semi-Rigid 4" Flexible
0 - 58 ft 28 ft
1 - 48 ft 23 ft
2 - 38 ft 19 ft
3 - 29 ft 17 ft
4 - 21 ft 15 ft

NOTE: It is recommended that you inspect your dryer ducting periodically to ensure you have no lint build up. Excessive lint can present a fire hazard.

Here’s some useful guidance for installing dryer ducting. Improperly installed ducting can cause the following:

GAS DRYERS – Rapid burn cycling and improper drying results.
ELECTRIC DRYERS – Premature Heating Element failures.

IMPORTANT! NEVER terminate ducting in a chimney, under an enclosed crawl space or attic, and never common a dryer duct with a kitchen exhaust.

The total length of ducting and number of turns should be kept to a minimum. Semi-rigid metal type ducting is strongly recommended as it is more durable and resists collapsing.

If connecting sections of ducting, all joints should be tight to avoid leaks. The male end of each section must point AWAY from the dryer to prevent lint from accumulating at each junction. Ductwork should NOT be assembled with screws or fasteners that extend INTO the duct as this also will create points where lint will become snagged and accumulate. Wrap overlapping sections of ducting with duct tape.

A screen should NEVER be installed over the exhaust duct termination. The preferred termination is a dampered wall cap having a 4 inch opening. It must be installed a minimum of 12 inches above the ground.

Maximum Length of Metal Duct:

# of 90 degree elbows 4” Semi-Rigid 4” Flexible
0 58 ft 28 ft
1 48 ft 23 ft
2 38 ft 19 ft
3 29 ft 17 ft
4 21 ft 15 ft

NOTE: It is recommended that you inspect your dryer ducting periodically to ensure you have no lint build up. Excessive lint can present a fire hazard.